Electronic apparatus in wireless communication system, and mobility measurement method

ABSTRACT

An electronic apparatus in a wireless communications system, and a mobility measurement method. The electronic apparatus includes a communications device and a mobility measurement device. The communication device is configured to separately perform dual-connection communication with two connection nodes by different carriers. The mobility measurement device is configured to perform mobility measurement, for determining a connection switching mode, on the connection nodes in the dual connections in a case in which connection service quality of at least one of the current dual connection nodes is lower than a preset level. The mobility measurement device is further configured to determine a reporting mode of a mobility measurement result according to the measurement condition of at least one of the current dual connection nodes.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.16/110,904, filed Aug. 23, 2018, which is a divisional of U.S.application Ser. No. 15/317,369 filed Dec. 8, 2016 (now U.S. Pat. No.10,334,655), which is a National Stage Application based onPCT/CN2015/080865, filed Jun. 5, 2015, and claims priority to ChinesePatent Application No. 201410283433.2 filed Jun. 23, 2014, all of whichare herein incorporated by reference in their entirety.

TECHNICAL FIELD

The disclosure generally relates to the field of wireless communication,and more particularly, to an electronic apparatus in a wirelesscommunication system and a method of performing mobility measurement bya mobile communication terminal.

BACKGROUND

At present, the following measurement events are defined in a LTE(long-term evolution)/LTE-A (advanced long-term evolution) system:

An A1 event, in which a serving cell has a quality higher than anabsolute threshold, for turning off an on-going inter-frequencymeasurement and deactivating a measurement gap.

An A2 event, in which a serving cell has a quality lower than anabsolute threshold, for turning on inter-frequency measurement andactivating a measurement gap.

An A3 event, in which a neighbor cell has a quality higher than that ofa main serving cell by an amount higher than an absolute threshold, fora coverage-based inter-frequency/intra-frequency handover.

An A4 event, in which a neighbor cell has a quality higher than anabsolute threshold, mainly for a load-based handover.

An A5 event, in which a main serving cell has a quality lower than afirst absolute threshold 1 and a neighbor cell has a quality higher thana second absolute threshold 2, for a coverage-basedinter-frequency/intra-frequency handover.

An A6 event, in which a neighbor cell has a quality higher than that ofa secondary serving cell by an amount higher than an absolute threshold,for a coverage-based inter-frequency secondary carrier adjustment.

A B1 event, in which a neighbor cell in a different system has a qualityhigher than an absolute threshold, for a load-based handover.

A B2 event, in which a serving cell has a quality lower than a firstabsolute threshold 1 and a neighbor cell in a different system has aquality higher than a second absolute threshold 2, for a coverage-basedhandover.

The A1/A2 event may be used for turning off or triggeringinter-frequency measurement by a terminal. The A3/A5/B2 event may beused for a coverage-based inter-system/intra-system handover. The A6event may be used for a coverage-based secondary carrier adjustment in ascenario of carrier aggregation. The A4/B1 event may be used for aload-based inter-system/intra-system handover.

SUMMARY

In a scenario of dual-connection, a terminal is simultaneously connectedto two base stations which have no ideal backhaul, such mobilityscenario is more complicated than that of a single base stationconnection or a dual-base station connection with ideal backhaul carrieraggregation. Therefore, embodiments of the disclosure are provided forthe above dual-connection scenario.

A brief summary of the embodiments of the present disclosure areprovided below to provide some basic understanding to some aspects ofthe present disclosure. It should be understood that the summary is notexhaustive, and is not intended to identify a crucial or important partof the present disclosure or limit the scope of the present disclosure.The only purpose is to give some conception in a simplified manner as aprelude to the detailed description provided later.

According to an aspect of the present disclosure, an electronicapparatus in a wireless communication system is provided. The electronicapparatus includes a communication device and a mobility measurementdevice. The communication device is configured for performingdual-connection communication with two connection nodes respectively viadifferent carriers. The mobility measurement device is configured forperforming mobility measurement on a connection node of currentdual-connection for determining a connection transfer mode, in a casethat a service quality of at least one of the current dual-connectionnodes is lower than a predetermined level. The mobility measurement isfurther configured for determining a mode for reporting a result of themobility measurement based on a measurement condition of at least one ofthe current dual-connection nodes.

According to another aspect of the present disclosure, a method ofperforming mobility measurement by a mobile communication terminal isprovided. The method includes a step of performing mobility measurementon current dual-connection nodes for determining a connection transfermode in a case that a service quality of at least one of the currentdual-connection nodes for the mobile communication terminalcommunicating in a dual-connection scenario is lower than apredetermined level. The method also includes a step of determining amode for reporting a result of the mobility measurement based on ameasurement condition of at least one of the current dual-connectionnodes.

The embodiments of the present disclosure are advantageous for improvingthe efficiency of reporting measurement for dual-connection.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure can be better understood by referring to thefollowing description taken in conjunction with the accompanyingdrawings. Same or similar reference characters indicate same or similarparts throughout the accompanying drawings. The accompanying drawingsare included in the description together with the followingspecifications as a part of the description for further illustratingpreferred embodiments with examples and explaining the principle andadvantages of the present disclosure. In the accompanying drawings:

FIG. 1 is a block diagram of a configuration example of an electronicapparatus according to an embodiment of the present disclosure;

FIG. 2 is a schematic diagram for illustrating connection transfermodes;

FIG. 3 is a schematic diagram for illustrating an example of timesequence relation between a T310 timer and a TTT timer;

FIG. 4 is a schematic diagram for illustrating an example of timesequence relation between TTT timers;

FIG. 5 is a schematic diagram for illustrating an example of timesequence relation between a TTT timer and a T310 timer;

FIG. 6 is a schematic diagram for illustrating an example of timesequence relation between a TTT timer and a T310 timer;

FIG. 7 is a schematic diagram for illustrating an example of timesequence relation between a TTT timer and a T310 timer;

FIG. 8 is a schematic diagram for illustrating an exemplary manner ofsignaling transmission for connection node transfer;

FIG. 9 is a schematic diagram for illustrating an exemplary manner ofsignaling transmission for connection node transfer;

FIG. 10 is a schematic diagram for illustrating an exemplary manner ofsignaling transmission for connection node transfer;

FIG. 11 is a schematic diagram for illustrating an exemplary manner ofsignaling transmission for connection node transfer;

FIG. 12 is a flowchart of a process example of a method according toanother embodiment of the present disclosure; and

FIG. 13 is a block diagram of an exemplary structure of a computerimplementing the method and apparatus according to the presentdisclosure.

DETAILED DESCRIPTION OF EMBODIMENTS

Embodiments of the invention are described below with reference to thecompanying drawings. Elements and features described in a companyingdrawing or an embodiment may be combined with elements and featuresillustrated in one or more other companying drawings or embodiments inthe present disclosure. It should be noted that presentation andexplanation of irrelevant components and processes known by thoseskilled in the art are omitted in the companying drawings and thedescription for clarity.

The technique according to the present disclosure can be applied tovarious products. For example, a base station can be implemented as anevolved Node B (eNB) of any types, such as a macro eNB or a small eNB.The small eNB maybe an eNB covering a cell smaller than a macro cell,such as a pico-eNB, a micro-eNB, and a home-eNB (femto-eNB).Alternatively, the base station can be implemented as a base station ofany other types, such as a NodeB or a base transceiver station (BTS).The base station may include a main body (also referred to as basestation equipment) configured to control wireless communications, andone or more remote radio heads (RRH) arranged at positions differentfrom the main body. Furthermore, each of various terminals to bedescribed below may operate as a base station by temporarily orsemi-persistently performing functions of a base station.

For example, the electronic apparatus may be implemented as a mobileterminal (such as a smart phone, a tablet personal computer (PC), alaptop PC, a portable game terminal, a portable/dongle mobile router ora digital camera device) or a vehicular terminal (such as a vehiclenavigating apparatus). A terminal apparatus 300 can also be implementedas a terminal performing machine-to-machine (M2M) communications (alsoreferred to as a machine-type communication (MTC) terminal).Furthermore, the electronic apparatus 100 may be a wirelesscommunication module (such as an integrated circuit module including asingle die) mounted in each of the above terminals.

Referring to FIG. 1, an electronic apparatus 100 in a wirelesscommunication system according to an embodiment of the presentdisclosure includes a communication device 110 and a mobilitymeasurement device 120.

The communication device 110 is configured for performingdual-connection communication with two connection nodes respectively viadifferent carriers.

For example, as shown in FIG. 2, an electronic apparatus U1 may performdual-connection communication with two connection nodes M1 and S1respectively via its communication device.

The mobility measurement device 120 is configured for performingmobility measurement on a connection node of current dual-connection fordetermining a connection transfer mode, in a case that a service qualityof at least one of the current dual-connection nodes is lower than apredetermined level. Furthermore, the mobility measurement device 120 isfurther configured for determining a mode for reporting a result of themobility measurement based on a measurement condition of at least one ofthe current dual-connection nodes.

In the present disclosure, the term “measurement condition” may includethe measurement result per se (such as a reference signal received power(RSRP), and a reference signal received quality (RSRQ), etc.), and mayalso include other measurement conditions, such as whether there is ameasurement list for a respective connection node, and a state of arespective started T310 timer and/or TTT timer, etc. As described withreference to specific embodiments below, the mobility measurement device120 may determine different modes for reporting a result of the mobilitymeasurement based on a measurement condition, so as to improve theefficiency of reporting measurement of dual-connection.

According to an embodiment, the mobility measurement may includemobility measurement configured for determining one of the followingconnection transfer modes:

Mode A: disconnecting from one of the current dual-connection nodes tochange from a dual-connection state into a single-connection state.

Mode B: maintaining connection to one of the current dual-connectionnodes, and transferring connection to the other node to a target node,to maintain a dual-connection state.

Mode C: disconnecting from both of the current dual-connection nodes,and transferring connection to a target node, to change from adual-connection state to a single-connection state.

Mode D: disconnecting from both of the current dual-connection nodes,and transferring connections to two target nodes, to maintain adual-connection state.

Mode E: maintaining connections to both of the current dual-connectionnodes, and adjusting secondary carriers of respective connection nodes.

Examples of the connection transfer modes are described more intuitivelybelow with reference to FIG. 2.

An apparatus U4, which is in a dual-connection with a macro base stationM2 and a small cell base station S4, may disconnect from one of theconnection nodes, for example, the small cell base station S4, andmaintain connection to the other connection node, for example, the macrobase station M2. This connection transfer mode corresponds to the abovementioned mode A. In another example, the mode A may also include a caseof disconnecting from the macro base station and maintaining connectionto the small cell base station.

An apparatus U3, which is in a dual-connection with a macro base stationM1 and a small cell base station S2, may disconnect from one of theconnection nodes, for example, the small cell base station S2, andtransfer to a connect to a small cell base station S3. This connectiontransfer mode corresponds to the above mentioned mode B. In anotherexample, the mode B may also include a case of transferring connectionto a source macro base station to a target macro base station.

An apparatus U5, which is in a dual-connection with the macro basestation M2 and a small cell base station S5, may disconnect from both ofthe macro base station M2 and the small cell base station S5, andtransfer to a connect to a macro base station M1. This connectiontransfer mode corresponds to the above mentioned mode C. In anotherexample, the mode C may also include a case of transferring the originaldual-connection to a connection to a target small cell base station.

An apparatus U2, which is in a dual-connection with a macro base stationM3 and a small cell base station S6, may disconnect from both of themacro base station M3 and the small cell base station S6, and transferto a dual-connection to a macro base station M2 and a small cell basestation S7. This connection transfer mode corresponds to the abovementioned mode D.

Particularly, for the transfer mode A, no comparison between targetnodes is necessary. The transfer may be triggered by, for example, theoccurrence of a radio link failure (RLF) over a main carrier of a singlenode, or a result of mobility measurement of RSRP/RSRQ over a maincarrier of the single node being lower than a threshold. For the lattercase, a trigger event for the mode A may be distinguished from anE-UTRAN A2 event. For example, a trigger event is defined specially forthe mode A.

According to an embodiment, the mobility measurement device 120 may beconfigured for reporting a mobility measurement result corresponding tothe connection transfer of the mode A in a case that a service qualityof one of the current dual-connection nodes is lower than a firstthreshold level. The first threshold level is not higher than athreshold level for triggering an A2 event.

With the above configuration, a condition for triggering aninter-frequency measurement by an A2 event is more permissive than thetrigger condition for the connection transfer of the mode A. Therefore,the A2 event may be triggered at a time earlier than the connectiontransfer of the mode A. The first threshold level may be specificallyset as required to appropriately determine an interval between thetriggering of the A2 event and the triggering of the connection transferof the mode A.

More specifically, an offset threshold may be additional defined, on thebasis of A2 event, for deactivating one of the connection nodes by adual-connection user. For example, information on the offset thresholdmay be broadcasted from the network to terminals. Alternatively, a setof parameters for a dual-connection user to deactivate one of theconnection nodes may be broadcasted from the network to terminals withreference to the definition of parameters for the A2 event. By the abovetwo exemplary approaches, a report triggering event may be speciallydesigned for the connection transfer of the mode A, or a manner forreporting the A2 event can be used to carry a condition (such as anRSRP/RSRQ measurement result) for triggering a report of the connectiontransfer of the mode A, for the network to determine on the deactivationof a node.

In the scenario of dual-connection, if an existing manner of measurementreport is used, the triggering of coverage-based measurement ischallenged in the following aspects.

Referring to the example as shown in FIG. 2 again, U1 and U3 performdual-connection data transmission in a supper dense small cellsdeployment. Adjacent cells may use different bands in order to avoidstrong interference between the small cells. In a case that the smallcells is far from a macro base station, when a UE moves to an overlappedregion between two small cells of different frequencies and performsinter-frequency measurement, the following situation may occurfrequently: both a macro cell and a low power node cell satisfyconditions of A3 to A6 events or B1 to B2 events with respect to atarget measurement small cell, and the events are reported to the macrocell and/or the low power node respectively. However, since the UE isstill in the coverage of the macro cell, the connection to the macrocell needs not to be transferred. Therefore, resources are wasted forunnecessarily reporting mobility measurement for comparing between aserving carrier of the low power node and a serving carrier of the macrobase station.

Furthermore, since U5 is at an edge of a macro cell, both a target macrocell (M1) and current dual-connection cells (M2 and S2) satisfy theA3/A5 event. Since U2 is at the edges of two macro cells (M3 and M2) andalso the edges of two small cells (S6 and S7), if a source macro cellsatisfies an A3/A5 event with respect to both a target macro cell and atarget small cell, then the time points for triggering mobilitymeasurement events of main carriers of the two connection nodes of thedual-connection may be different, the connection node transfer operationsignaling interaction and data transmission which are performedseparately for different reports may be further complicated if theevents are reported respectively with a very short time interval.Therefore, it is necessary to define separate trigger events for thescenarios, and simplify the entire operation process for thetransmission structure and procedures of user plane data as shown inFIG. 3 for example.

According to an embodiment, the mobility measurement device 120 may beconfigured for performing mobility measurement on the two connectionnodes respectively, and determining the triggering of a mobilitymeasurement report according to a comparison of measurement results onmeasuring objects for the first node and second node of the currentdual-connection nodes, in a case that a predetermined condition issatisfied.

Next, the manner of determining the triggering of a mobility measurementreport according to a comparison of measurement results on measuringobjects of the current dual-connection nodes is described with referenceto a specific embodiment.

In a specific embodiment, the first measuring object for the first nodemeasured by the mobility measurement device 120 may include aninter-frequency inter-system measuring object for the first node and anintra-frequency measuring object for a connection carrier of the firstnode which are received from the first node. Similarly, the secondmeasuring object for the second node measured by the mobilitymeasurement device 120 may include an inter-frequency inter-systemmeasuring object for the second node and an intra-frequency measuringobject for a connection carrier of the second node which are receivedfor the second node. For example, the measurement objects of differentconnection nodes may be determined according to inter-frequencymeasurement/inter-system measurement lists for respective nodes.

Accordingly, the mobility measurement device 120 may be configured forperforming the mobility measurement based on the first measuring objectand the second measuring object respectively, comparing a measurementresult of a first measuring object with a measurement result of a secondmeasuring object to determine whether a measurement reporting conditionis satisfied, and reporting the measurement result and/or a measurementcomparison result of the measuring objects if a carrier of the firstnode or the second node satisfies the measurement reporting condition.The measurement result and/or the measurement comparison result may bereported only to the node corresponding to the measurement object, oronly to a macro node, or to both of the connection nodes.

In the scenario of dual-connection, the network may configure a terminalapparatus to perform inter-frequency measurement on any connection nodeshaving any carriers that satisfy a condition for reporting the A2 event.On the other hand, an intra-frequency measurement result of a carrier ofa first connection node may be considered as an inter-frequencymeasurement result of a second connection node, and an inter-frequency(inter-system or intra-system) measurement result of the firstconnection node may also be considered as an inter-frequency measurementresult of the second connection node. Similarly, an intra-frequencymeasurement result of a carrier of the second connection node may beconsidered as an inter-frequency measurement result of the firstconnection node, and vice versa. With the embodiment, the measurementresult is appropriately reported by referring to the mobilitymeasurement results of both of the connection nodes, which may avoidreporting repeated information in a case that the measurement objectsfor the two connection nodes include a same target node. Therefore,unnecessary frequent reports of the A3/A4/A5/A6/B1/B2 event can beavoided, thereby the number of triggering of measurement reports in thescenario of dual-connection can be optimized.

According to another specific embodiment, the mobility measurementdevice 120 may be configured for comparing a measurement result of thefirst node with a measurement result of the second node to decidewhether a triggering condition of an E-UTRAN A3/A4/A5/B1/B2 event issatisfied in a case that the first node satisfies at least one of thefollowing conditions:

1.1) at least one of the first node and the second node satisfies thetriggering condition of the A2 event.

1.2) for the first node, there is no measuring object forinter-frequency measurement or inter-system measurement.

1.3) a T310 timer started for a main carrier of the first node exceeds apredetermined time limit and an A3/A4/A5/B1/B2 TTT timer for the firstmeasuring object has not been started yet, or the TTT timer has beenstarted but is turned off within a predetermined time limit.

Here, the measurement result of a node refers to a result of mobilitymeasurement performed for the node, which may include a result ofmeasurement on a signal transmitted by a measuring object (such as thefirst measurement object) related to the node. As mentioned above, themeasuring object of the node may be determined based on information onan inter-frequency inter-system measuring object regarding the node andinformation on an intra-frequency measuring object for a connectioncarrier of the node which are received from the node.

Regarding the above condition 1.1), the comparison between themeasurement result of the first node and the measurement result of thesecond node may be performed directly in a case that one of thedual-connection nodes has a service quality lower than a threshold forthe A2 event.

Regarding the above condition 1.2), the comparison of measurementresults may be performed directly in a case that, for example, one ofthe dual-connection nodes does not have a mobility measurement list, sothat the measurement result of the measuring object of the other nodecan be used.

Regarding the above condition 1.3), the comparison of measurementresults may be performed directly in a case that one of thedual-connection nodes has a high possibility of link failure and thereis no candidate target node, so that the measurement result of themeasuring object of the other node can be used.

Accordingly, the comparison of measurement results between nodes may bestopped according to a predetermined condition. According to a specificembodiment, the mobility measurement device 120 may be configured forstopping comparison with the measurement result of the second node, andturning off a corresponding A3/A4/A5/B1/B2 TTT timer which has beentriggered, the comparison of measurement results of a main carrier ofthe first node is limited to comparison with frequency points of thefirst measuring objects, in a case that the first node satisfies atleast one of the following conditions:

2.1) a main carrier of the first node satisfies a condition fortriggering report of an A1 event; and

2.2) a T310 timer for a main carrier of the first node is turned offbefore the T310 timer expires, or an A3/A4/A5/B1/B2 TTT timer related tothe first measuring object is started before a predetermined time limitexpires from the start of the T310 timer, or the TTT timer has beenstarted and operation time of the TTT timer exceeds a predeterminedlimit.

Regarding the above condition 2.1), since the service quality of thenode is recovered, the comparison with measurement result of the othernode may be stopped.

Regarding the above condition 2.2), since the possibility of linkfailure of the node is small or a candidate target node is likely toexist, the comparison with measurement result of the other node may bestopped.

Particularly, according to an embodiment, the mobility measurementdevice 120 is configured for performing, for mobility measurementcorresponding to a connection transfer of the mode E, the mobilitymeasurement and report only for a frequency point contained in ameasuring object of inter-frequency measurement or inter-systemmeasurement of each of the current dual-connection nodes, therebyensuring proper handover to a secondary carrier in the node withoutunnecessary reporting.

Furthermore, while a TTT timer for a single node is started fortriggering a report of a traditional handover event, another channelquality monitoring procedure, i.e., RLF monitoring is also performed.For example, referring to FIG. 3, the TTT timers (for example, TTTtimers 1-4) started for individual nodes may have different timerelations with a RLF T310 timer. Furthermore, certain time dependencymay exist among different nodes, which may be helpful for determining ameasurement report corresponding to which mode of transfer to betriggered.

According to an embodiment, the mobility measurement device 12 may beconfigured for directly triggering a measurement result report and/ormeasurement comparison result report corresponding to connectiontransfer of the mode C in a case that a first node of the currentdual-connection nodes satisfies a condition for triggering report of theA3/A4/A5/B1/B2 event, and the A3/A4/A5/B1/B2 TTT timer and/or a T310timer started for a second node of the current dual-connection nodessatisfies a predetermined condition.

In other words, in a case that the first node satisfies a condition ofconnection transfer, if the timer for the second node satisfies apredetermined condition (such as specific conditions described withreference to specific embodiment below), it is unnecessary to wait forexpiration of a timer for the second node to perform the measurementresult report corresponding to the connection transfer of the mode C.The report may indicate that the first node satisfies a condition fortransferring to a target node and the second node may be disconnectedfrom. Therefore, the system may decide, according to the measurementresult, to disconnect from both of the current dual-connection nodes andtransfer to the target node, thereby changing from a dual-connectionstate to a single connection state. With this configuration, thecomplicity of reporting measurement results may be reduced.

In the following, an example of the above predetermined condition isdescribed with reference to specific embodiments.

According to a specific embodiment, the measurement result reportcorresponding to the mode C is directly performed if the followconditions are satisfied:

3.1) the first node first satisfies a condition for triggering report ofthe A3/A4/A5/B1/B2 event;

3.2) at this time, the expiration-waiting-time of an A3/A4/A5/B1/B2 TTTtimer for a main carrier of the second node is less than a predeterminedthreshold; and

3.3) a measuring target node of the first node is the same as that ofthe second node.

Herein, the term “expiration-waiting-time” refers to a differencebetween a current time and an expected expiration time of a timer. Inother words, the shorter the expiration-waiting-time is, the closer tothe expiration of a timer.

If the above condition 3.1) is satisfied, it is indicated that the firstnode has an available target node for transfer (which may be aninter-system or intra-system node).

If the above condition 3.2) is satisfied, it is indicated that thesecond node is highly possible to have an available target node fortransfer. Referring to FIG. 4, the condition 3.2) is satisfied ifT_(B)-T_(A)≤Δ_(TTT), where the current time is the time when a TTT timerTTT_(A) for the first node is expired (i.e., the time point T_(A) inFIG. 4), and the expiration-waiting-time of a TTT timer TTT_(B) for thesecond node is denoted by T_(B).

If the above condition 3.3) is satisfied, it is indicated that theconnection is to be transferred to the same target node even if the TTTtimer for the second node expires.

Therefore, if the above conditions are satisfied, the measurement resultreport corresponding to the connection transfer of the mode C may bedirectly performed without waiting for the expiration of the timer forthe second node. Therefore, the system may decide, according to themeasurement result, to disconnect from both of the currentdual-connection nodes and transfer to the target node.

In another embodiment, a measurement result report corresponding to themode C is directly performed and the report indicates that the targetnode for transfer is a target node of the first node in a case that thefollowing conditions are satisfied:

4.1) the first node first satisfies a condition for triggering report ofan A3/A4/A5/B1/B2 event;

4.2) at this time, the expiration-waiting-time of an A3/A4/A5/B1/B2 TTTtimer for a main carrier of the second node is less than a predeterminedthreshold; and

4.3) at this time, the expiration-waiting-time of a T310 timer for thesecond node is not greater than that of the TTT timer by a predeterminedthreshold or more.

If the above condition 4.1) is satisfied, it is indicated that the firstnode has an available target node for transfer.

If the above condition 4.2) is satisfied, it is indicated that thesecond node is highly possible to have an available target node fortransfer. Referring to FIG. 5, the condition 4.2) is satisfied if a timeT_(A) when a TTT timer TTT_(A) for the first node is expired and theexpiration-waiting-time T_(B) of a TTT timer TTT_(B) for the second nodesatisfy T_(B)-T_(A)≤Δ_(TTT).

If the above condition 4.3) is satisfied, it is indicated that even ifthe TTT time for the second node expires, a link failure is highlypossible to occur in a time not sufficient for completing the connectiontransfer. Referring to FIG. 5, the condition 4.3) is satisfied ifT_(C)-T_(B)≤Δ_(T310), where the expiration-waiting-time of the T310timer for the second node is denoted as T_(C).

Therefore, in a case that the above conditions are satisfied, themeasurement result report corresponding to the connection transfer ofthe mode C may be directly performed without waiting for the expirationof the TTT timer or the T310 timer for the second node. Therefore, thesystem may decide, according to the measurement result, to disconnectfrom both of the current dual-connection nodes and transfer to thetarget node.

In another embodiment, a measurement result report corresponding to themode C is directly performed and the report indicates that the targetnode for transfer is a target node of the first node, in a case that thefollowing conditions are satisfied:

5.1) the first node first satisfies a condition for triggering report ofan A3/A4/A5/B1/B2 event;

5.2) at this time, the expiration-waiting-time of a T310 timer for thesecond node is less than a predetermined threshold.

If the above condition 5.1) is satisfied, it is indicated that the firstnode has an available target node for transfer.

If the above condition 5.2) is satisfied, it is indicated that a linkfailure is likely to occur to the second node soon. Referring to FIG. 6,the condition 5.2) is satisfied if T_(C)-T_(A)≤Δ′_(T310), where theexpiration-waiting-time of the T310 timer for the second node is denotedas T_(C).

Therefore, in a case that the above conditions are satisfied, themeasurement result report corresponding to the connection transfer ofthe mode C may be directly performed without wait for the expiration ofthe TTT timer or the T310 timer for the second node. Therefore, thesystem may decide, according to the measurement result, to disconnectfrom both of the current dual-connection nodes and transfer to thetarget node of the first node.

In the above specific embodiments, the thresholds Δ_(TTT), Δ_(T310),Δ′_(T310) may be set specifically according to requirements. Forexample, the time thresholds may be set by referring to the time neededfor performing the connection transfer, and may be notified to themobility measurement device by a serving carrier of the connection nodevia a broadcast message or a dedicated RRC/MAC.

Embodiments of reporting directly without waiting for the expiration ofa timer for the second node in a case that the measurement conditionsatisfies a certain condition are described above. In anotherembodiment, the mobility measurement device 120 may be configured forwaiting for the expiration of an A3/A4/A5/B1/B2 TTT timer for a secondnode in a case that a first node of the current dual-connection nodessatisfies a condition for triggering report of an A3/A4/A5/B1/B2 event,and the A3/A4/A5/B1/B2 TTT timer started for the second node of thecurrent dual-connection nodes and a T310 timer started for the firstnode and/or the second node satisfy a predetermined condition.

In other words, in a case that a first node satisfies a condition ofconnection transfer, if timers of the first node and the second nodesatisfy a certain condition (such as the condition described below withreference to specific embodiments), the expiration of the timer for thesecond node is waited for. Therefore, the system can determine theconnection transfer mode based on measurement results of both of thenodes. With the embodiment, it can be ensured to determine theconnection transfer mode more properly based on measurement result ofboth the nodes in certain cases.

According to a specific embodiment, the expiration of a TTT timer forthe second node is waited for in a case that the condition fortriggering the report of an A3/A4/A5/B1/B2 event is satisfied for thefirst node and the following conditions are satisfied:

6.1) the expiration-waiting-time of the A3/A4/A5/B1/B2 TTT timer startedfor a main carrier of the second node is less than a predeterminedthreshold; and

6.2) the expiration-waiting-time of the T310 timer started for the firstnode and/or the second node is greater than the expiration-waiting-timeof the TTT timer for the second node by a predetermined threshold ormore.

If the above condition 6.1) is satisfied, it is indicated that thesecond node is highly possible to have an available target node fortransfer. For example, referring to FIG. 7, the condition 6.1) issatisfied because the expiration time T_(A) of the timer TTT_(A) for thefirst node and the expiration-waiting-time T_(B) of the TTT timerTTT_(B) for the second node satisfy the condition T_(B)-T_(A)≤Δ_(TTT).

If the above condition 6.2) is satisfied, it is indicated that a linkfailure will not occur soon to the first node and/or the second node.For example, referring to FIG. 7, the condition 6.2) is satisfiedbecause the expiration time T_(C) of a T310 timer (which may be startedfor the first node and/or the second node) satisfies the conditionT_(C)-T_(B)≤Δ_(TTT).

Furthermore, in a case that the above conditions for waiting for theexpiration of a TTT timer for the second node are satisfied, if the TTTtimer for the second node is turned off due to a fact that the channelquality of the second node is recovered during the waiting for theexpiration of the TTT timer, the measurement result report correspondingto the mode B may be performed for the measurement triggering event ofthe first node.

In other words, in a case that the first node satisfies the condition ofconnection transfer, if the service quality of the second node isrecovered, the report may indicate that the first node satisfies acondition for transferring to the target mode and connection to thesecond node may be maintained. Therefore, the system may decide,according to the measurement result, to maintain the connection to thesecond node of the current dual-connection nodes and transfer theconnection to the first node to connection to the target node of thefirst node, thereby maintaining a dual-connection state.

Furthermore, in a case that the above conditions for waiting for theexpiration of a TTT timer for the second node are satisfied, if the TTTtimer for the second node expires, corresponding reporting manners canbe determined based on the following measurement conditions:

7.1) in a case that target nodes of TTT events for main carriermeasurement of the first node and the second node are different, ameasurement result report corresponding to the mode D is performed, or ameasurement result report corresponding to the mode C is performed witha target node of a macro node serving as the target node for transfer.

7.2) in a case that target nodes of TTT events for main carriermeasurement of the first node and the second node are the same,performing a measurement result report corresponding to the mode C.

Regarding the case 7.1), since the two nodes have different availabletarget nodes for transfer, the report may indicate that each of thefirst node and the second node satisfies a condition for transferring toa respective target node. The system may decide, according to themeasurement result, to disconnect from both of the dual-connectionnodes, and transfer to the two target nodes, thereby maintaining adual-connection state. Alternatively, the system may decide, accordingto the measurement result, to disconnect from both of thedual-connection nodes, and transfer to a target node of a macro node,thereby maintaining a single-connection state.

Regarding the above case 7.2), since the two nodes have the sameavailable target node for transfer, the report may indicate that boththe first node and the second node satisfy the condition fortransferring to the same target node. Therefore, the system may decide,according to the measurement result, to disconnect from both of thecurrent dual-connection nodes and transfer to the target node, therebychanging from a dual-connection state to a single-connection state.

Furthermore, according to an embodiment, the condition for waiting forthe expiration of the TTT timer for the second node may further include:the measurement trigger reporting event for the second node is acoverage-based mobility trigger reporting event. In other words, it isrequired that the measurement on the second node is coverage-basedmobility measurement for waiting for the expiration of the TTT timer forthe second node after the expiration of the TTT timer for the firstnode, while the measurement of the first node may be coverage-basedmobility measurement or load-based mobility measurement. With thisconfiguration, it is avoid that a report of coverage-based measurementwaits for a report of load-based measurement, thereby having a morereasonable mobility measurement reporting manner.

In addition to the above measurement conditions described with referenceto the above embodiments, there may be another condition that both ofthe dual-connection nodes satisfy a condition for triggering a report.According to an embodiment, the mobility measurement device 120 may beconfigured for, in a case that main carriers of both of the currentdual-connection nodes satisfy a condition for triggering report of anA3/A4/A5/B1/B2 event, not transferring the connection to the two nodes,but performing a measurement result report corresponding to the mode Baccording to a priority order, or performing a measurement result reportcorresponding to the mode D in order to decide a preferred transferringnode by the network. In other words, the report may indicate that one ofthe nodes satisfies the condition for transferring to the target node,and connection to the other node may be maintained. Therefore, thesystem may decide, according to the measurement result, to maintainconnection to which one of the current dual-connection nodes andtransfer the connection to the other node to a target node, therebymaintaining a dual-connection state. For the other node, measurementresult of the other node may be reported after a certain time or afterreceipt of a node transferring command from the network. Thisconfiguration is advantageous for reducing the complicity of measurementreport.

Specifically, the priority order may be determined according to one ormore of the following principles:

8.1) the one having a worse channel quality of source node is prior;

8.2) the one having a better signal of target node is prior;

8.3) a coverage-based measurement event is prior to a load-basedmeasurement event;

8.4) a node whose T310 timer expires earlier is prior; and

8.5) a macro node is prior to a low power node.

With the principles 8.1) and 8.2), the transfer mode is selectedaccording to channel quality, which may achieve better channel qualityby the node transfer. With the principles 8.3) and 8.5), it is ensuredthat more important node has higher priority to be transferred. With theprinciple 8.4), it is ensured that a node that is more likely to havelink failure has higher priority to be transferred. With thisconfiguration, the report may be performed according to the channelquality or the importance of nodes, thereby having a more reasonablemobility measurement reporting manner.

Furthermore, considering that a macro node is mainly for maintaining thenetwork connection and a low power node is mainly for data distribution,preferably, load-based measurement report can be performed mainly for alow power node and coverage-based measurement report can be performedfor both of the connection nodes.

Therefore, according to an embodiment, the mobility measurement device120 is configured for reporting a load-based event only for a low powernode.

Particularly, in a case that a measurement report corresponding to theconnection transfer mode C and the connection transfer mode D (i.e.,disconnecting from both of dual-connection nodes and transferring theconnection to one or more target nodes) occurs in various temporalrelations combinations, the mobility measurement device 120 may beconfigured for reporting a new report triggering event or reporting bycombining traditional A3/A4/A5/B1/B2 events. Furthermore, the mobilitymeasurement device 120 may report in various manners. For example, it ispossible to report measurement results of connection nodes to respectiveconnection nodes (i.e., to report measurement result of the first nodeto the first node and report measurement result of the second node tothe second node), or report measurement results of all connection nodesto both of the connection nodes (i.e., to report measurement results ofthe first and second nodes to both of the first and second node).Furthermore, it is possible to report measurement results of both nodesonly to a macro node, or report measurement results of both nodes to themacro node while reporting a measurement result of a main carrier of alow power node to the low power node, as will be described withreference to FIG. 8 to FIG. 11 below.

According to an embodiment, the mobility measurement device 120 isconfigured for, if radio link failure occurs to a node of the currentdual-connection nodes before receipt of a node transfer notice and anode transfer event report is performed for the node, reporting to thenetwork via the other node of the current dual-connection nodes afterwaiting for over a predetermined time limit, and waiting for transfernotice signaling sent from the network via the other node within thetime limit. Alternatively, report can be made directly to the othernode, and node transfer operation is made based on a notice from theother node.

Furthermore, the node for reporting a measurement result and receiving aconfirmation for connection transfer may be determined according to astate of a T310 timer or TTT timer started for a connection node.

According to an embodiment, the mobility measurement device 120 may beconfigured for sending a measurement report and receiving a confirmationfor connection transfer via a first node and/or a second node of thecurrent dual-connection nodes, that is, sending a measurement report andreceiving a confirmation for connection transfer via any one or both ofthe two nodes, in the following case:

9.1) the expiration-waiting-times of T310 timers for the first node andthe second node are both greater than a predetermined threshold; or

9.2) for the first node and the second node, the expiration-waiting-timeof a T310 timer is greater than that of a TTT timer by a predeterminedthreshold or more.

As mentioned above, the expiration-waiting-time is a difference betweena current time and an expected expiration time of a timer. Below, it isassumed that the current time is the expiration time of the TTT timerfor the first node, and T310 _(A) denotes the expiration-waiting-time ofthe T310 timer for the first node, T310 _(B) denotes theexpiration-waiting-time of the T310 timer for the second node, andTTT_(B) denotes the expiration-waiting-time of the TTT timer for thesecond node.

If the conditions in the case 9.1) are satisfied, that is, T310_(A)≥Δ_(A) and T310 _(B)≥Δ_(B), it is indicated that no link failurewill occur soon to any of the two connection nodes. Therefore, thesending of a measurement report and reception of a confirmation forconnection transfer may be performed by any one or both of theconnection nodes.

If the conditions in the case 9.2) are satisfied, that is, T310_(A)-TTT_(B)≥Δ′_(A) and T310 _(B)-TTT_(B)≥Δ′_(B), it is indicated thatthere may be sufficient time between the determination of availabletarget node for transfer and occurrence of link failure. Therefore, thesending of a measurement report and reception of a confirmation forconnection transfer may be performed by any one or both of theconnection nodes.

In another embodiment, the mobility measurement device 120 may beconfigured for sending a measurement report and receiving a confirmationfor connection transfer via a first node of the current dual-connectionnodes in the following case:

10.1) the expiration-waiting-time of a T310 timer for the first node isgreater than a predetermined threshold, and the expiration-waiting-timeof a T310 timer for a second node of the current dual-connection nodesis less than a predetermined threshold; or

10.2) for the first node, the expiration-waiting-time of a T310 timer isgreater than that of a TTT timer by a predetermined threshold or more,and for the second node, the expiration-waiting-time of a T310 timer isnot greater than that of a TTT timer by a predetermined threshold ormore.

If the conditions in the case 10.1) are satisfied, that is, T310_(A)≥Δ_(A) and T310 _(B)<Δ_(B), it is indicated that no link failurewill occur soon to the first nodes, while a link failure may likelyoccur soon to the second node. Therefore, the sending of a measurementreport and reception of a confirmation for connection transfer may beperformed by the first nodes.

If the conditions in the case 10.2) are satisfied, that is, T310_(A)-TTT_(B)≥Δ′_(A) and T310 _(B)-TTT_(B)<Δ′_(B), it is indicated thatthere may be sufficient time between the determination of availabletransfer target node and occurrence of link failure for the first node,while there may not be sufficient time between the determination ofavailable transfer target node and occurrence of link failure for thesecond node. Therefore, the sending of a measurement report andreception of a confirmation for connection transfer may be performed bythe first node.

Similarly, the mobility measurement device 120 may be configured forsending a measurement report and receiving a confirmation for connectiontransfer via the second node of the current dual-connection nodes in thefollowing case:

11.1) the expiration-waiting-time of a T310 timer for the second node isgreater than a predetermined threshold, and the expiration-waiting-timeof a T310 timer for the first node of the current dual-connection nodesis less than a predetermined threshold; or

11.2) for the second node, the expiration-waiting-time of a T310 timeris greater than that of a TTT timer by a predetermined threshold ormore, and for the first node, the expiration-waiting-time of a T310timer is not greater than that of a TTT timer by a predeterminedthreshold or more.

In another embodiment, the mobility measurement device 120 may beconfigured for sending a measurement report or receiving a confirmationfor connection transfer via both of a first node and a second node ofthe current dual-connection nodes in the following case:

12.1) the expiration-waiting-times of T310 timers of the first node andthe second node are both less than a predetermined threshold; or

12.2) for the first node and the second node, theexpiration-waiting-time of a T310 timer is not greater than that of aTTT timer by a predetermined threshold or more.

If the conditions in the case 12.1) are satisfied, that is, T310_(A)<Δ_(A) and T310 _(B)<Δ_(B), it is indicated that a link failure mayoccurs soon to both of the connection nodes. Therefore, the sending of ameasurement report and reception of a confirmation for connectiontransfer need to be performed by both of the nodes, to improve thepossibility of success in signaling transmission.

If the conditions in the case 12.2) are satisfied, that is, T310_(A)-TTT_(B)<Δ′_(A) and T310 _(B)-TTT_(B)≥Δ′_(B), it is indicated thatthere may not be sufficient time between the determination of availabletransfer target node and occurrence of link failure. Therefore, thesending of a measurement report and reception of a confirmation forconnection transfer also need to be performed by both of the nodes, toimprove the possibility of success in signaling transmission.

In the above embodiments, the time thresholds, such as, the thresholdsΔ_(A), Δ_(B), Δ′_(A), Δ′_(B), may be set according to practicalconditions. For example, the time threshold may be set by referring to atime needed for performing the connection transfer, to ensure apredetermined probability of success in signaling transmission. Thethresholds are notified to the mobility measurement device by theserving carrier of the connection node via a broadcast message ordedicated RRC/MAC.

The scenarios may be reported separately or may be reported as a type ofscenarios that may be processed with a same principle (such as the 4cases classified as the above). Specifically, if the cases arerepresented with a 0/1 bitmap, the number of added information bits isthe number of the cases. If the added information bits are representedin the binary, the added information is 4 bits or 2 bits. Accordingly,the network may perform a process control according to the timesequences corresponding to the cases.

Next, exemplary signaling transmission for transferring connection nodesare described with reference to FIG. 8 to FIG. 11. FIG. 8 and FIG. 9correspond to the connection transfer mode C (i.e., the mode ofdisconnecting from both of the dual-connection nodes and transferringconnection to one target node). FIG. 10 and FIG. 11 correspond to theconnection transfer mode D (i.e., the mode of disconnecting from both ofthe dual-connection nodes and transferring connection to two targetnodes).

Referring to FIG. 8, a UE may send a measurement report to a macro nodebased on a result of channel state monitoring. Furthermore, referring tothe conditions (for example, 9.1) or 9.2), 12.1) or 12.2)) describedabove, the UE may send the measurement report to a secondary node.Additionally, the macro node may send the received measurement report tothe secondary node.

Then, a node transfer request may be sent to a target node by the macronode and/or the secondary node. If the request is approved, the targetnode sends acceptance signaling to the macro node and/or the secondarynode, and then the macro node and/or the secondary node sends aconfirmation for node transfer to the UE.

Referring to FIG. 9, for example, referring to the conditions (forexample, 10.1) or 10.2), 11.1) or 11.2)) described above, a UE may senda measurement report only to a macro node based on a result of channelstate monitoring.

Then, a node transfer request may be sent to a target node by the macronode. If the request is approved, the target node sends acceptancesignaling to the macro node, and the macro node sends a confirmation fornode transfer to the UE.

It should be noted that, although FIG. 9 illustrates that themeasurement report and the confirmation for node transfer are sent bythe macro node, the measurement report and the confirmation for nodetransfer may also be sent by the secondary node if the secondary nodesatisfies a corresponding condition.

Referring to FIG. 10, for example, referring to the conditions (forexample, 10.1) or 10.2), 11.1) or 11.2)) described above, a UE may senda measurement report to a source macro node based on a result of channelstate monitoring.

Then, a node transfer request may be sent to a target macro node and atarget secondary node by the source macro node. If the request isapproved, the target macro node and the target secondary node sendacceptance signaling to the source macro node, and then the source macronode sends a confirmation for node transfer to the UE.

Although FIG. 10 illustrates that the measurement report and theconfirmation for node transfer are sent by the source macro node, themeasurement report and the confirmation for node transfer may also besent by the source secondary node if the source secondary node satisfiesa corresponding condition.

Referring to FIG. 11, for example, referring to the conditions (forexample, 9.1) or 9.2), 12.1) or 12.2)) described above, a UE may send ameasurement report to a source macro node and a source secondary nodebased on a result of channel state monitoring.

Then, a node transfer request may be sent to a target macro node and atarget secondary node by the source macro node and the source secondarynode. If the request is approved, the target macro node and the targetsecondary node send acceptance signaling to the source macro node andthe source secondary node, and the source macro node and the sourcesecondary node send a confirmation for node transfer to the UE.

Apparently, the above description of the embodiments of the electronicapparatus also discloses some processing and methods. A summary of themethods is provided below without repeating some details discussedabove.

Referring to FIG. 12, a method of performing mobility measurement by amobile communication terminal according to an embodiment of the presentdisclosure includes:

performing (S1220) mobility measurement on current dual-connection nodesfor determining a connection transfer mode in a case that a servicequality of at least one of the current dual-connection nodes for themobile communication terminal communicating in a dual-connectionscenario is lower than a predetermined level (Y in S1210); and

determining (1230) a mode for reporting a result of the mobilitymeasurement based on a measurement condition of at least one of thecurrent dual-connection nodes.

The connection transfer mode may include at least one of the connectiontransfer modes A to E described above.

According to an embodiment, a mobility measurement result correspondingto the connection transfer of the mode A is reported in a case that aservice quality of one of the current dual-connection nodes is lowerthan a first threshold level. The first threshold level is lower than athreshold level for triggering an E-UTRAN A2 event.

In another embodiment, the triggering of a mobility measurement reportis determined according to a comparison of measurement results for thefirst connection node and second connection node of the currentdual-connection nodes, in a case that a predetermined condition issatisfied.

Specifically, the first measuring object for the first node may includean inter-frequency inter-system measuring object for the first node andan intra-frequency measuring object for a connection carrier of thefirst node which are received from the first node; and the secondmeasuring object for the second node may include an inter-frequencyinter-system measuring object for the second node and an intra-frequencymeasuring object for a connection carrier of the second node which arereceived for the second node.

The mobility measurement may be performed on the first measuring objectand the second measuring object respectively, and a measurement resultof the measuring object for the first node may be compared with ameasurement result of the measuring object for the second node todetermine whether a measurement reporting condition is satisfied. Themeasurement result of the measuring object of the second node isreported to the first node if a condition for reporting the measurementresult to the first node is satisfied.

Furthermore, a measurement result of the first node may be compared witha measurement result of the second node to decide whether a triggeringcondition of an E-UTRAN A3/A4/A5/B1/B2 event is satisfied in a case thatthe first node satisfies at least one of the following conditions: atleast one of the first node and the second node satisfies the triggeringcondition of the A2 event; for the first node, there is no measuringobject for inter-frequency measurement or inter-system measurement; anda T310 timer started for a main carrier of the first node exceeds apredetermined time limit and an A3/A4/A5/B1/B2 TTT timer for the firstmeasuring object has not been started yet, or the TTT timer has beenstarted but is turned off within a predetermined time limit.

Furthermore, the comparison with the measurement result of the secondnode may be stopped, a corresponding A3/A4/A5/B1/B2 TTT timer which hasbeen triggered may be turned off, and the comparison of measurementresults of a main carrier of the first node may be limited to comparisonwith frequency points of the first measuring objects, in a case that thefirst node satisfies at least one of the following conditions: a maincarrier of the first node satisfies a condition for triggering report ofan Al event; and a T310 timer for the main carrier of the first node isturned off before the T310 timer expires or an related A3/A4/A5/B1/B2TTT timer is started before a predetermined time limit expires from thestart of the T310 timer, or the TTT timer has been started and operationtime of the TTT timer exceeds a predetermined limit.

According to an embodiment, for mobility measurement corresponding to aconnection transfer of the mode E, the mobility measurement and reportare performed only for a frequency point contained in a measuring objectof inter-frequency measurement or inter-system measurement of thecurrent dual-connection nodes.

In another embodiment, a mobile terminal directly performs a measurementresult report corresponding to the mode C in a case that a first node ofthe current dual-connection nodes satisfies a condition for triggeringreport of an A3/A4/A5/B1/B2 event, and an A3/A4/A5/B1/B2 TTT timerand/or a T310 timer started for a second node of the currentdual-connection nodes satisfies a predetermined condition.

Specifically, a measurement result report corresponding to the mode Cmay be directly performed in a case that the following conditions aresatisfied: the first node first satisfies a condition for triggeringreport of the A3/A4/A5/B1/B2 event; meanwhile theexpiration-waiting-time of an A3/A4/A5/B1/B2 TTT timer for a maincarrier of the second node is less than a predetermined threshold; and ameasuring target node of the first node is the same as that of thesecond node.

Furthermore, a measurement result report corresponding to the mode C maybe directly performed and it is indicated that the target node fortransfer is a target node of the first node in a case that the followingconditions are satisfied: the first node first satisfies a condition fortriggering report of an A3/A4/A5/B1/B2 event; meanwhile theexpiration-waiting-time of an A3/A4/A5/B1/B2 TTT timer for a maincarrier of the second node is less than a predetermined threshold; andmeanwhile the expiration-waiting-time of a T310 timer for the secondnode is not greater than that of the TTT timer by a predeterminedthreshold or more.

Furthermore, a measurement result report corresponding to the mode C maybe directly performed and it is indicated that the target node fortransfer is a target node of the first node in a case that the followingconditions are satisfied: the first node first satisfies a condition fortriggering report of an A3/A4/A5/B1/B2 event; meanwhile theexpiration-waiting-time of an A3/A4/A5/B1/B2 TTT timer for a maincarrier of the second node is greater than a predetermined threshold;and meanwhile the expiration-waiting-time of a T310 timer for the secondnode is less than a predetermined threshold.

According to an embodiment, a mobile communication terminal waits forthe expiration of an A3/A4/A5/B1/B2 TTT timer for a second node in acase that a first node of the current dual-connection nodes satisfies acondition for triggering report of an A3/A4/A5/B1/B2 event, and theA3/A4/A5/B1/B2 TTT timer started for the second node of the currentdual-connection nodes and a T310 timer started for the first node and/orthe second node satisfy a predetermined condition.

More specifically, the expiration of the TTT timer for the second nodemay be waited for in a case that the condition for triggering the reportof an A3/A4/A5/B1/B2 event is satisfied for the first node and thefollowing conditions are satisfied: the expiration-waiting-time of theA3/A4/A5/B1/B2 TTT timer started for a main carrier of the second nodeis less than a predetermined threshold; the expiration-waiting-time ofthe T310 timer started for the first node and/or the second node isgreater than the expiration-waiting-time of the TTT timer for the secondnode by a predetermined threshold or more.

More specifically, a measurement result report corresponding to the modeB is performed for the measurement triggering event of the first node ifthe TTT timer for the second node is turned off because the channelquality of the second node is recovered during the waiting for theexpiration of the TTT timer.

Furthermore, if the TTT timer for the second node expires: a measurementresult report corresponding to the mode D is performed in a case thattarget nodes of TTT events for main carrier measurement of the firstnode and the second node are different; a measurement result reportcorresponding to the mode C is performed in a case that target nodes ofTTT events for main carrier measurement of the first node and the secondnode are the same.

Furthermore, the condition for waiting for the expiration of the TTTtimer for the second node may also include: the measurement triggerreporting event for the second node is a coverage-based mobility triggerreporting event.

In another embodiment, in a case that main carriers of both of thecurrent dual-connection nodes satisfy a condition for triggering reportof an A3/A4/A5/B1/B2 event, a priority order for reporting may bedetermined based on one or more of the following principles: the onehaving a worse channel quality of source node is prior; the one having abetter signal of target node is prior; a coverage-based measurementevent is prior to a load-based measurement event; a node whose T310timer expires earlier is prior; and a macro node is prior to a low powernode.

Preferably, a load-based event may be reported only for a low powernode.

According to an embodiment, if radio link failure occurs to one of thecurrent dual-connection nodes before receipt of a node transfer notice,one of the following rules are followed to operate: reporting to thenetwork via the other node of the current dual-connection nodes afterwaiting for over a predetermined time limit, and waiting for transfernotice signaling sent from the network via the other node within thetime limit; and directly reporting to the other node, and performingnode transfer operation based on a notice from the other node.

In another embodiment, the sending of a measurement report to andreception of a confirmation for connection transfer are performed via afirst node and/or a second node of the current dual-connection nodes ina case that: the expiration-waiting-times of T310 timers for the firstnode and the second node are both greater than a predeterminedthreshold; or for the first node and the second node, theexpiration-waiting-time of a T310 timer is greater than that of a TTTtimer by a predetermined threshold or more.

In another embodiment, the sending of a measurement report to andreception of a confirmation for connection transfer are performed via afirst node of the current dual-connection nodes in a case that: theexpiration-waiting-time of a T310 timer for the first node is greaterthan a predetermined threshold, and the expiration-waiting-time of aT310 timer for a second node of the current dual-connection nodes isless than a predetermined threshold; or for the first node, theexpiration-waiting-time of a T310 timer is greater than that of a TTTtimer by a predetermined threshold or more, and for the second node, theexpiration-waiting-time of a T310 timer is not greater than that of aTTT timer by a predetermined threshold or more.

In another embodiment, the sending of a measurement report to andreception of a confirmation for connection transfer are performed viaboth a first node and a second node of the current dual-connection nodesin a case that: the expiration-waiting-times of T310 timers of the firstnode and the second node are both less than a predetermined threshold;or for the first node and the second node, the expiration-waiting-timeof a T310 timer is not greater than that of a TTT timer by apredetermined threshold or more.

As an example, various steps of the above methods and various componentsand/or units of the above device may be implemented in software,firmware, hardware or a combination thereof. In a case of implementingin software or firmware, a program of a software for implementing theabove methods may be installed from a storage medium or a network to acomputer (such as the general-purpose computer 1300 shown in FIG. 13)having dedicated hardware structure. The computer can perform variousfunctions if installed with various programs. In a case of implementingthe above device in software, the device may be configured by a softwaredesign. In a case of implementing the above device in hardware, thedevice may be configured by a hardware design or combination. In a caseof implementing the above device in a combination of software andhardware, the device may be configured by a design combining softwareand hardware.

In FIG. 13, a computation processing unit (i.e., a CPU) 1301 executesvarious processing according to a program stored in a Read Only Memory(ROM) 1302 or a program loaded to a Random Access Memory (RAM) 1303 froma storage section 1308. In the RAM 1303, if necessary, data required forthe CPU 1301 in executing various processing and the like is alsostored. The CPU 1301, the ROM 1302 and the RAM 1303 are linked to eachother via a bus 1304. An input/output interface 1305 is also linked tothe bus 1304.

The following components are linked to the input/output interface 1305:an input section 1306 including a keyboard, a mouse and the like, anoutput section 1307 including a display such as a Cathode Ray Tube (CRT)and a Liquid Crystal Display (LCD), a speaker and the like, the storagesection 1308 such as a hard disk and the like, and a communicationsection 1309 such as a network interface card like a LAN card, a modemand the like. The communication section 1309 performs communicationprocessing via a network such as the Internet. If necessary, a drive1310 can also be linked to the input/output interface 1305. A removablemedium 1311 such as a magnetic disk, an optical disk, a magneto-opticaldisk, a semiconductor memory and the like is mounted on the drive 1310as required such that a computer program read out therefrom is installedin the storage section 1308 as required.

In a case that the series of processing above is implemented insoftware, a program constituting the software is installed from thenetwork such as the Internet or the storage medium such as the removablemedium 1311.

It is understood by those skilled in the art that the storage medium isnot limited to the removable medium 1311 shown in FIG. 13 in which theprogram is stored and which is distributed separately from the apparatusso as to provide the program to the user. Examples of the removablemedium 1311 include a magnetic disk including a Floppy Disk (registeredtrademark), an optical disk including a Compact Disk Read Only Memory(CD-ROM) and a Digital Versatile Disc (DVD), a magneto-optical diskincluding a MiniDisc (MD) (registered trademark), and a semiconductormemory. Alternatively, the storage medium may be the ROM 1302, the harddisk contained in the storage section 1308 or the like, in which theprogram is stored, and is distributed to the user together with theapparatus containing the storage medium.

Embodiments of the present disclosure also relates to a program producton which machine-readable instruction codes are stored. The instructioncodes can perform the methods according to the above embodiment whenread and executed by a machine.

Accordingly, the present disclosure also includes storage mediumcarrying the program product on which the machine-readable instructioncodes are stored. The storage media includes a soft-disk, an opticaldisk, a magnetic disk, a storage card, a storage stick and the like, butis not limited thereto.

Embodiments of the present disclosure also include an electronicapparatus. The electronic apparatus includes a circuit. The circuit isconfigured to perform mobility measurement on current dual-connectionnodes for determining a connection transfer mode in a case that aservice quality of at least one of current dual-connection nodes for themobile communication terminal communicating in a dual-connectionscenario is lower than a predetermined level. The circuit is furtherconfigured to determine a mode for reporting a result of the mobilitymeasurement based on a measurement condition of at least one of thecurrent dual-connection nodes.

In the above description of embodiments of the present disclosure, afeature described and/or illustrated in an embodiment may be applied toone or more other embodiments in a same or similar manner, or may becombined with a feature in other embodiments, or may replace a featurein other embodiments.

It should be emphasized that, the term “include/contain”, as used in thepresent disclosure, means existence of a feature, an element, a step ora component, but does not exclude existence or addition of one or moreother features, elements, steps or components.

In the above examples and embodiments, numeric reference characters areused for representing various steps and/or units. Those skilled in theart should understand that the reference characters are only used forfacilitating description and illustration rather than representing anorder or other limits.

Furthermore, the methods in the present disclosure are not limited to beperformed in the time order as described, but may be performed in othertime orders or in parallel or independently. Therefore, the performingorder of the method described in the present disclosure is not a limitto the technical scope of the present disclosure.

Although the invention is disclosure by describing the above embodimentof the present disclosure, it should be noted that each of the aboveexample and embodiment is not for limiting but for illustrating. Thoseskilled in the art may make various modifications, improvements andequivalents within the spirit and scope of the appended claims. Themodifications, improvements and equivalents should also be included inthe protection scope of the present disclosure.

1. An electronic device in a wireless communication system, theelectronic device comprising circuitry, configured to communicate with afirst node and a second node via different carriers for dualconnectivity; detect a radio link failure on a primary carrier signal ofthe second node; generate a report indicating the radio link failure tothe first node; and perform a measurement result report corresponding toa mode of (i) maintaining connection to one of the first and secondnodes and (ii) transferring connection to other node to a target node,to maintain a dual-connection state, in a case that primary carriersignals of any one of the first and second nodes satisfy a condition fortriggering report of a first event, a second event, a third event, afourth event, or a fifth event, report of the first event, the secondevent, the third event, the fourth event, or the fifth event, based onone or more of following principles: the one having a worse channelquality of source node is prior; the one having a better signal oftarget node is prior; a coverage-based measurement event is prior to aload-based measurement event; a node whose timer expires earlier isprior; and a macro base station node is prior to a low power node.